The test log shows flaky failures of this test several times a day on
QNX, so blacklist it.
To do that, we need to be able to isolate the "GUI" mode of this test.
To do that, add a single data tag that depends on whether the test
project is built for GUI or Core, and blacklist only the "gui" data tag.
Task-number: QTBUG-119359
Pick-to: 6.6
Change-Id: I91c2380de0a3febedcf781f27fed4a1fa6aa5515
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
d2c6e9ab99